Osmunda japonica Thunb.

Picture 1 in Japan, Honshu, Tokyo, May 2008 (cultivated)
Pictures 2, 3 & 4 in Japan, Honshu, Nagano, June 2010
Pictures 5 & 6 in Japan, Honshu, garden in Obuse, June 2010
Picture 7 in Taiwan, Lushan Valley, 24 November 2013